COURSE CODE :: BCOM 11 COURSE ::COMPUTER APPLICATIONS IN BUSINESS

Unit -1 :: INTRODUCTION TO COMPUTERS

INTRODUCTION The term computer is derived from the word compute,

which means to calculate. In simple words, a computer is an electronic device, which takes input from the user in the form of data, processes that data according to the instructions given by the user, and displays the output on the screen.

Computers are now used in almost all the domains including business, academics, defense, budgeting, research, engineering, medicine, and space exploration. Apart from maintaining the day-to-day records of an organization, computer also helps to perform various other tasks, such as generating the revenue and comparing the annual sales records of the organization.

OBJECTIVES Learn about computer and its features Explore the evolution of computer Know about the basic parts of a computer Learn about the different types of computers Explore about computer hardware and software

components

DEFINITION AND CHARACTERISTICS OF COMPUTER

A computer is a machine that accepts the input in form of data or information, and processes it according to the instructions provided by the user to produce the desired output.

A computer consists of software and hardware devices that interact with each other to produce the desired output.

The following are some of the characteristics of a computer: Speed: Refers to the rate at which a computer performs all its operations. A

computer processes all the computations in fractions of seconds. Storage and reliability: Refers to the storage capacity of a computer, that

is, how much information can be stored in a computer. The reliability feature helps the computer to generate the output at the location specified by a user.

Accuracy: Refers to the degree of accurate results generated by the computer.

Versatility: Allows you to use computers in almost every field or domain, such as teaching, training, entertainment, accounting, and hospitality, to perform the desired task.

EVOLUTION OF COMPUTERS

AbacusThe term Abacus came from a calculating tool used in ancient days by the merchants of Asian and African continents to perform arithmetic calculations. ENIAC and EDVACElectronic Numerical Integrator and Computer (ENIAC) was the first electronic computer introduced in February 19, 1946. It could perform 5,000 additions or subtraction and 360 multiplications in just one second. Electronic Discrete Variable Automatic Computer (EDVAC), was based on a new concept of storing information in a large internal memory IBM Personal ComputerIn late 1970s, IBM decided to provide computers to common people and developed one in 1981 with considerable lesser size and cost than its predecessors. IBM called it a PC.

GENERATIONS OF COMPUTER First generation computers (1940-1956)The first generation computers used vacuum tubes for circuitry and magnetic drums for memory. The computers of first generation relied on machine languages to perform operations and could solve only one problem at a time. Second generation computers (1956-1963) In the second generation of computers, vacuum tubes of the first generation of computers were replaced by transistors. The computers of second generation were small, fast, and precise in making calculations, and consumed less electricity. In addition, the computers of second generation also included printers, primary memory, and storage media to save documents and operating systems. Third generation computers (1964-1971) Integrated Circuit (IC) was developed in the third generation of computers. In this generation, users interacted with computers with the help of keyboards, monitors, and Operating System (OS). Fourth generation computers (1971-Present) The major contribution of the fourth generation of computers came in 1971 when Intel, a major chip manufacturer, came up with its own chip known as 4004. The 4004 chip of Intel was one step ahead than IC, as it brought CPU, memory, and input and output controls under a single chip. Fifth generation computersThe major contribution of the fifth generation computer is artificial intelligence.

CLASSIFICATION OF COMPUTERS

Computer for IndividualsThe computer that is meant for single accessibility, that is used by a single user, at a point of time is known as the computer for individuals. The types of computers that are meant for individual use are:

Desktop computer Handheld computer Notebook computer Tablets PCs Smart phones

Computers for OrganizationsThese computers are used by large enterprises and organizations, such as insurance and banking, to perform multiple tasks simultaneously. Some examples of the computers used by organizations are listed as follows:

Mainframe computers Super computers Minicomputers Microcomputers Self-destructing computers

PROCESSORS USED IN PCs

System UnitThe system unit is the most important part of a computer system. All devices, such as keyboard, mouse, monitor, printer, and speakers, are linked to the system unit through cables, which are plugged into the back of the system unit. Basic Input Output SystemBIOS is a built-in software, which keeps track of all devices, such as keyboard, monitor, and disk drives attached to a computer and provides an intercommunication channel between them. MemoryThe term memory stands for data storage that is in the form of chips, and the term storage is used for memory that exists on tapes or disks. Hard DisksHard disk is considered as the non-volatile, random access drive used to store data in digital form.

COMPUTER SOFTWARESSoftware is a set of computer programs and related data that are used to provide instructions to a computer to perform a specific task. System softwareThe system software consists of programs, languages, and documentation supplied to the end user by the manufacturer of the computer. Application software An application software mainly focuses on executing a particular set of functions or instructions provided by the user.

DESCRIBING COMPUTER HARDWARE

The input devices are those devices (hardware equipment) that are used to enter data, commands, programs, and various user responses into the computer system. There are different types of input devices, such as keyboard, mic to input voice data, web-camera for video input, and mouse as a pointing device, all of which together are referred as an input unit.

The output device is an electronic equipment connected to a computer and is used to communicate the results of the data processing. The different output devices are monitor, plotters, printer, and speakers.

A computer system also consists of some other hardware devices that you can use to communicate with other people over the Internet. These include mode, web camera, Headphone, and Mike.

COMPUTER LANGUAGESA computer understands only the instructions given by a programmer in a predefined format, known as the programming language. The generations of languages can be divided into the following categories:  First Generation Languages — 1GLs (Machine Languages)In the machine language, instructions contain long strings of 0s and 1s. The symbol (1) in the string is interpreted by the computer as the presence of the electric pulse, whereas the symbol (0) is interpreted as the absence of the electric pulse. Second Generation Languages — 2GLs (Assembly Languages)An assembly language is similar to the English language and is in a human readable format. Third Generation Languages — 3GLs (High-level Languages)3GLs are simple to understand by humans, as they include easy to learn syntax for developing a program. Fourth Generation Languages (4GLs)A programmer using a 4GL just needs to decide about the tasks that must be performed by the program; the rest is taken care of by the predefined built-in functions.

THE LANGUAGE PROCESSOR

a language processor is responsible for translating one type of language into another type of language. Let’s now discuss three important language processors:

Assembler: Converts the man-readable data to machine-readable data.

Compiler: Converts a complete program from a high-level language to machine language.

Interpreter: Converts the code written in a high-level language into machine language code, line by line.

NETWORKA network is an arrangement in which two or more computers are connected in such a way that they are able to communicate with each other. The networks modes are as follows: The Peer-to-Peer NetworkThe peer-to-peer network is a group of user-oriented computers and each computer connected in this network is called a peer. Peers share resources, such as files and printers; however, no specialized server exists. The Client/Server Network In the client/server network, computers provide services to each other. This network model allows users to access information, resources, and services located anywhere within the client/server network. The Hybrid Network The hybrid network refers to a combination of two or more networks. This can include several star networks that are connected by the bus or ring topology, or several ring networks connected by the bus topology.

SUMMARY A computer is a machine that accepts the input in form of data or information, and

processes it according to the instructions provided by the user to produce the desired output.

A computer consists of various components, such as CPU, monitor, mouse, and keyboard. The system unit is the most important part of a computer system. It resembles a

rectangular box containing some buttons and disk drives at the front side, and sockets of different shapes and sizes at the back side.

BIOS is a built-in software, which keeps track of all devices, such as keyboard, monitor, and disk drives attached to a computer and provides an intercommunication channel between them.

The physical components of a computer are known as computer hardware. Some hardware components are already attached to a computer, such as monitor and keyboard; however, depending upon your requirements, you can also install additional hardware components, such as scanner or printer.

A device that lets you enter data or instructions in a computer is known as an input device.

The output device is an electronic equipment connected to a computer and is used to communicate the results of the data processing.

A computer understands only the instructions given by a programmer in a predefined format, known as the programming language.

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